In recent years, the applicant of the present invention has made significant improvements to the constructions of conventional syringes in view of the deficiencies found in the injection operation procedure using conventional syringes and has filed several patent applications in China and other countries. The subject matters of these patent applications filed by the applicant previously involve this and other improvements to the conventional syringes for medical use. However, most of the syringes disclosed in these patent applications do not have the function of instant automatic injections for emergency circumstances, so they are not practical for the needs of instant injection under circumstances such as battlefield self-rescue or other emergent cases. In addition, no prior art discloses an automatic syringe using powder drugs. Powder drugs which often have better curative effects than liquid drugs are not widely used for automatic injection under emergent self-rescue. Conventional syringes are not suitable for emergent injections outside medical facilities because of the complicated drug mixing and adding operation procedures and the risk of contamination.
Chinese patent application No. 200510096467.1 filed by the applicant on Dec. 5, 2005 entitled “Automatic Syringe for Instant Liquid-Powder Drug Mixing” discloses an automatic syringe for solid powder drugs comprising an injecting assembly, a drug mixing assembly, a shooting device and a joining mechanism in which the injecting assembly including a solute vial containing solid powder drug, the drug mixing assembly including a menstruum bottle containing liquid menstruum, the shooting device including a push rod, a pawl and a spring assembly, and the joining mechanism including a central rotary axle and a axle sleeve. The central rotary axle is fixed to the injecting assembly and the axle sleeve is fixed between the drug mixing assembly and the shooting device. The central rotary axle is inserted into the axle sleeve so that the drug mixing assembly and the shooting device can rotate around the central rotary axle so as to alternatively connect with the drug-mixing assembly to complete the drug mixing operation and the automatic injection operation in turn.
Chinese patent application No. 200620079616.3 filed by the applicant on Aug. 22, 2006 entitled “Rotary Automatic Syringe for Instant Liquid-Powder Drug Mixing” discloses major improvements to the injecting assembly, the drug mixing assembly, the shooting device and the joining mechanism of the above-mentioned automatic syringe disclosed in 200510096467.1. A cutting ring and a protective ring are added to the injecting assembly. A returning spring is added to the drug mixing assembly. The push rod in the shooting device includes a push rod for needing feeding, a push rod for injection and a retractable rod. Accordingly two springs are provided in stead—one for the needle feeding push rod and the other for the injection push rod. And two axle sleeves of the joining mechanism having open ends are provided for the drug mixing assembly and the shooting device respectively. And the central rotary axle and injecting assembly are now connected through the axle sleeve having open end in stead of the fixed connection disclosed in 200510096467.1. The above modifications greatly improve the function and effects of the automatic syringe.
The present invention claims priorities of the above-mentioned two Chinese patent applications.